Kidney injury molecule-1 (KIM-1), a putative epithelial cell adhesion molecule containing a novel immunoglobulin domain, is up-regulated in renal cells after injury.
We report the identification of rat and human cDNAs for a type 1 membrane protein that contains a novel six-cysteine immunoglobulin-like domain and a mucin domain; it is named kidney injury molecule-1 (KIM-1). Structurally, KIM-1 is a member of the immunoglobulin gene superfamily most reminiscent of mucosal addressin cell adhesion molecule 1 (MAdCAM-1). Human KIM-1 exhibits homology to a monkey gene, hepatitis A virus cell receptor 1 (HAVcr-1), which was identified recently as a receptor for the hepatitis A virus. KIM-1 mRNA and protein are expressed at a low level in normal kidney but are increased dramatically in postischemic kidney. In situ hybridization and immunohistochemistry revealed that KIM-1 is expressed in proliferating bromodeoxyuridine-positive and dedifferentiated vimentin-positive epithelial cells in regenerating proximal tubules. Structure and expression data suggest that KIM-1 is an epithelial cell adhesion molecule up-regulated in the cells, which are dedifferentiated and undergoing replication. KIM-1 may play an important role in the restoration of the morphological integrity and function to postischemic kidney.
Ichimura
T
T
Renal Unit, Medical Services, Massachusetts General Hospital East, Boston, Massachusetts 02129, USA.
Bonventre
J V
JV
Bailly
V
V
Wei
H
H
Hession
C A
CA
Cate
R L
RL
Sanicola
M
M
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015815:Cell Adhesion Molecules / Q000737:chemistry*; D003001:Cloning, Molecular; D005786:Gene Expression Regulation / Q000235:genetics; D007136:Immunoglobulins / Q000737:chemistry*; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D007511:Ischemia / Q000378:metabolism; D007668:Kidney / Q000737:chemistry / Q000293:injuries*; D008297:Male; D008565:Membrane Proteins; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D011994:Recombinant Proteins / Q000235:genetics; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D015854:Up-Regulation / Q000502:physiology
D015815:Cell Adhesion Molecules; D007136:Immunoglobulins; D008565:Membrane Proteins; D012333:RNA, Messenger; D011994:Recombinant Proteins; C110936:Havcr1 protein, rat